Arrangement of a motor on a support winch

ABSTRACT

An arrangement of a motor on twin landing gears is described. The landing gears are interconnected via a connecting shaft and can be telescoped by starting up the motor. To minimize damage to the motor and at the same time to ensure cost-effective production, it is provided that the motor with its driveshaft engages with the connecting shaft and is supported on a component that is fixed relative to the motor.

CROSS REFERENCE

This application is a division of application Ser. No. 10,655,320, filedon Sep. 4, 2003, now U.S. Pat. No. 7,036,847 of Jose Alguera et al. forARRANGEMENT OF A MOTOR ON A SUPPORT WINCH, which claims priority toGerman Application Serial No. 10241905.1, filed Sep. 6, 2002.

FIELD OF THE INVENTION

The invention relates to an arrangement of a motor on twin landinggears, particularly on a semi-trailer of a tractor-trailer, such thatthe landing gears are interconnected via a connecting shaft and can betelescoped by starting up the motor.

BACKGROUND OF THE INVENTION

After coupling or uncoupling the semi-trailer, the landing gears aretelescoped, i.e. they are extended or retracted, and support thestanding semi-trailer. This extending and retracting of the landinggears is usually done by the driver using a hand crank that is mountedon one of the landing gears. To relieve the driver of this physicallystrenuous work, efforts are being made to apply the power required toretract and extend the landing gears by a motor.

Such an arrangement of a motor on a landing gear is disclosed in EP 0179 632. The motor is mounted to one of the landing gears from theoutside—in place of the hand crank—to a primary shaft of the landinggear gearbox. The essential drawback of the power-driven landing gear ofthe prior art is that the motor is mounted on the outside of the landinggear in an unprotected area and, in practice, is frequently damaged. Afurther drawback is that the motor must be designed for a low speed anda high speed of the landing gear, which entails substantial motor designcomplexity because it requires either a motor control or an additionalmotor speed.

SUMMARY OF THE INVENTION

Thus, the object of the invention is to provide an arrangement of amotor that minimizes damage to the motor and at the same time can beproduced cost-effectively.

According to the invention, this object is attained by an arrangement inwhich the motor with its driveshaft engages with the connecting shaftand is supported on a component that is fixed relative to the motor.

By supporting the motor on a fixed component, co-rotation of the motoris effectively prevented and, as a result, a rotation of the connectingshaft is realized.

By positioning the motor on the connecting shaft, the problem ofadjusting the motor to the typically two-speed gearbox of the landinggear is solved by arranging the motor behind the gearbox in the line offorce. As a result it is possible, in turn, to use commerciallyavailable, simply constructed motors.

A further advantage of the arrangement according to the invention isthat the motor is mounted in a protected area between the landing gears,in the case of semi-trailers underneath the semi-trailer floor and thuscannot be easily damaged during travel.

Furthermore, the landing gears do not need to be modified forretrofitting, or the manufacturer can use the same components fordifferent landing gear types.

In a special embodiment, a spring element is arranged between the motorand the fixed component.

The spring element prevents damage to the motor when the landing geardrives against its upper or lower limit stop as the motor is stillcoasting due to its centrifugal mass. The elasticity of the springelement protects the motor against an abrupt load, especially whendriving against the upper hard limit stop, but also when starting up themotor. This extends the life of the motor and also allows the use ofless expensive motors.

The spring element preferably is a spiral spring, particularly a coilspring, a torsion element or a shock absorber. The spiral spring can beinstalled in its axial extension or can be used as a torsion element.The term shock absorber should be understood as including springbuffers.

A torsion element may also be an elastic hose or an elastic tube.

The fixed component is advantageously at least one of the two landinggears and in this case especially preferably the rear side of thelanding gear mounting plate by means of which the landing gear isscrewed to the semi-trailer.

The spiral spring or the torsion element is advantageously non-rotatablymounted to at least one of the landing gears and to the motor, such thatwhen the landing gear is driven against a limit stop, the entire motoris gently supported in its direction of rotation.

The spiral spring or the torsion element preferably surrounds theconnecting shaft at least partially.

It has proven to be particularly advantageous if the connecting shaft isarranged contactless within the spiral spring or the torsion element.This prevents friction losses between the connecting shaft and thespiral spring or the torsion element as the landing gear is telescoped.

In an alternative embodiment, the fixed component is the underside ofthe semi-trailer floor. In this case, the spiral spring or the shockabsorber can be arranged between the motor and the underside of thesemi-trailer floor.

It has proven to be advantageous if the spiral spring has an upper and alower partial spring arranged on a guide tube, and the outer ends ofthese partial springs can be fixed by an end stop. Between the upper andthe lower partial spring, a mounting bushing is arranged on the guidetube. Preferably, the mounting bushing or the shock absorber isconnected with the motor at a stop point. This stop point may allow themotor to pivot relative to the mounting bushing. When the landing gearis extended, the motor, due to its startup torque, could, for example,compress the upper partial spring via the mounting bushing, so that anabrupt loading of the motor and the components in the line of forcedownstream thereof is avoided. When the landing gear is extendedcompletely, the foot of the landing gear touches the ground, i.e. thelanding gear has reached its lower limit stop. The motor, however,continues to rotate for a brief time because of its centrifugal mass, sothat the mounting bushing again presses against the upper partial springand an abrupt loading is consequently avoided. Since the motor changesits direction of rotation when the landing gear is retracted, the lowerpartial spring is compressed both during startup and when drivingagainst the upper limit stop.

Advantageously, the guide tube is placed onto an inner tube and can beconnected with the inner tube in different positions in axial direction.This makes it possible to adjust and adapt the guide tube to the spatialconditions of the specific application to ensure optimized cooperationof the mounting bushing clamped by the partial springs and the motorfixed at the stop point.

In the above-described embodiments, the connecting shaft can benon-rotatably mounted on the driveshaft. This makes it possible torealize a loss-free and maintenance-free power transmission.

In a further advantageous embodiment, a spring element is arrangedbetween the driveshaft and the connecting shaft. In contrast to theabove-described embodiments, an elastic element is introduced directlyin the line of force between the driveshaft of the motor and theconnecting shaft.

The spring element can be an elastic sleeve, a belt drive or a slipcoupling. The elastic sleeve is made of an elastic material, e.g.rubber.

The elastic sleeve is advantageously configured as an air chambersleeve. This air chamber sleeve comprises an inner circumferential walladapted to the outer wall of the connecting shaft and an outercircumferential wall adapted to the inner wall of the driveshaft. Theinner and outer circumferential walls are connected via radiallyextending partitions that are spaced apart from one another. Airchambers are formed between the partitions. If shock-like forces occur,a damping effect is achieved due to the material properties and thematerial displacement by applying a force in circumferential direction.

In a particularly preferred embodiment, the fixed component consists ofat least one of the landing gears, a semi-trailer floor or a structuralmember of the vehicle, such that the fixed component is rigidlyconnected with the motor.

This has the advantage, first of all, that a smaller clearance isrequired because there are no spring elements that elastically supportthe motor. In particular, the space available between the connectingshaft and the underside of the semi-trailer floor is often tight. Due tothe rigid mounting of the motor, incoming lines to the motor do not haveto be flexible. A further safety aspect is that there are no movingparts on the outside. In addition, the weight forces of the motor aresupported via the fixed mounting and are not transmitted via theconnecting shaft to the bearings of the landing gear, which wouldotherwise be subject to greater wear.

Advantageously, the elastic sleeve is non-rotatably mounted on theconnecting shaft and the driveshaft. This can be accomplished, forexample, by bonding or vulcanizing.

In one advantageous embodiment, the belt drive has a drive belt whichloops around a driving wheel that is non-rotatably mounted on thedriveshaft and a driven wheel that is non-rotatably mounted on theconnecting shaft.

The drive belt can be made of an elastic material.

As an alternative to an elastic drive belt, a fixed, flexibly mountedtension roller can engage with a drive belt that has little elasticity.In the quasi-stationary operating state, i.e. as the landing gear istelescoped, a pretensioning force is applied to the drive belt via theflexibly mounted tension roller. When the landing gear reaches a limitstop, the tension roller is pushed back by the drive belt and thusdampens the shock-like load.

In a further advantageous embodiment, the slip coupling has a drivinggear wheel with internal teeth, which is mounted on the driveshaft andengages with a complementary driven gear wheel with external teeth,which is mounted on the connecting shaft. The driving gear wheel and/orthe driven gear wheel are mounted on the driveshaft or the driven shaftin a non-positive fit with a predefined friction coefficient. In case ofan abrupt load, at least one of the gear wheels slips on its shaft incircumferential direction and thereby prevents the shock from beingtransmitted to the motor.

It has proven to be particularly advantageous if the driveshaft isconfigured as a hollow shaft. This has the advantage that the commonlyused connecting shaft can be pushed through the driveshaft configured asa hollow shaft and as a result can continue to be used to a limitedextent.

The hollow shaft can have a circular cross section. This, in turn,simplifies the power transmission from the motor to the driveshaft.

The motor is preferably not self-locking, i.e. in case of a powerfailure or some other malfunctioning of the motor, the landing gear canstill be moved by means of a hand crank as before.

The motor preferably is an electric motor. An electric motor iscost-effective, low-maintenance, compact and easy to connect by means ofa power cable, independent of a compressed air supply.

The motor is advantageously designed for a torque of 5 to 15 Nm.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in greater detail, by way ofexample, with reference to the drawing figures, in which:

FIG. 1 is a schematic back view of an arrangement of a motor on theconnecting shaft with fixed support relative to a landing gear,

FIG. 2 is a partial view of an elastic support of the motor on a landinggear,

FIG. 3 is a perspective view of an elastic support of the motor on thesemi-trailer,

FIG. 4 is a back view of a support according to FIG. 3,

FIG. 5 is a longitudinal section of the motor with driveshaft, elasticsleeve and connecting shaft,

FIG. 6 is a cross section of an air chamber sleeve, and

FIG. 7 is a schematic side view of a belt drive.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows twin landing gears 2 a, 2 b arranged on a semi-trailer 3,which touch the ground when extended. A hand crank 29 may be seen on thelanding gear 2 a, which can be used to move the landing gears 2 a, 2 bif the motor 1 fails. The landing gears 2 a, 2 b are screwed to thesemi-trailer 3 via a landing gear mounting plate 31. Each of the landinggears 2 a, 2 b, is equipped with a landing gear gearbox.

The motor 1 is disposed on the connecting shaft 4 that interconnects thetwo landing gears 2 a, 2 b and with its driveshaft 5 non-rotatablyencloses the connecting shaft 4. Via a spring element 6, which in thepresent case is configured as a torsion element 8, the motor 1 iselastically connected with the landing gear 2 b and at the same time issecured against co-rotation. The torsion element can also be configuredas an elastic hose 10 or an elastic tube.

In FIG. 2, the motor 1 is elastically connected with the landing gear 2b by means of a spiral spring 7 instead of a torsion element 8. Theconnecting shaft 4 runs through the center of the spiral spring 7.

FIG. 3 is a perspective view of an alternative embodiment in which themotor 1 is supported on the underside of a semi-trailer floor 11 (seeFIG. 1) by means of a spring element 6.

In a center area of the motor, the rotatable driveshaft 5 protrudes onboth sides.

The motor 1 is supported via the stop point 17 and the mounting bushing16, which in turn is clamped between the upper partial spring 14 and thelower partial spring 15. The partial springs 14, 15 are each placed ontoa guide tube 9 and are fixed at their outer ends 13 a, 13 b by means ofend stops 12 a, 12 b.

To enable the spring element 6 to be mounted on structurally differentsemi-trailers, the guide tube 9 can be mounted so as to be displaceablein axial direction 19. For this purpose, the adjusting bolts 35 arepulled out, the guide tube 9 and the partial springs 14, 15 as well asthe mounting bushing 16 are shifted relative to the inner tube 18, whichcan be mounted to the underside of the semi-trailer (not depicted) bymeans of the mounting plate 32, and the adjusting bolts 35 arereinserted in the desired position, e.g. in one of the different visiblepositions 20 a, 20 b, 20 c. Thus, the position of the motor 1 can beadapted to a predefined position of the connecting shaft 4 without anychange in the elastic properties of the spring element 6.

FIG. 4 shows the spring element 6 and the motor 1 in a back view, sothat the motor 1 covers the upper and lower partial springs 14, 15. Thespring element 6 is connected with the bolting plate 32 by means of ascrewed connection 33.

FIG. 5 is a section of a motor 1, wherein a spring element 6 in the formof an elastic sleeve 21 is arranged between the driveshaft 5 and theconnecting shaft 4. The elastic sleeve 21 is brought out of the motor 1on one side and has a bore 36 that extends through the elastic sleeve 21and the connecting shaft 4, through which a connecting bolt 34 ispushed. By means of the connecting bolt 34, the elastic sleeve 21 andthe connecting shaft 4 are interconnected in a positive lockingconnection and are thus secured against rotation. The driveshaft 5 isalso connected with the elastic sleeve 21, e.g. by bonding.

In the embodiment according to FIG. 5, the motor 1 can be rigidlymounted to the underside of the semi-trailer floor 11, since theelasticity required when the landing gear 2 a, 2 b is driven against alimit stop is provided between the driveshaft 5 and the connecting shaft4.

FIG. 6 shows an air chamber sleeve 24 as a special form of the elasticsleeve 21. By way of example, the air chambers 24 a are shown in arelaxed state, while the air chambers 24 b are depicted under load. Theair chamber sleeve 24 is non-rotatably mounted between the driveshaft 5and the connecting shaft 4.

An alternative spring element 6 is shown in FIG. 7 in the form of a beltdrive 22. Here, a driving wheel 26 drives a driven wheel 27 via a drivebelt 25. The driving wheel 26 is non-rotatably connected with thedriveshaft 5 while the driven wheel 27 is non-rotatably connected withthe connecting shaft 4.

Tension rollers 28 engage with the drive belt 24 from the outside onboth sides to pretension the belt. As the landing gear 2 a, 2 b istelescoped against a limit stop, the drive belt 25 presses against oneof the tension rollers 28 such that the impact is absorbed.

LIST OF REFERENCE NUMERALS

-   1 motor-   2 a, b landing gear-   3 semi-trailer-   4 connecting shaft-   5 driveshaft-   6 spring element-   7 spiral spring-   8 torsion element-   9 guide tube-   10 elastic hose-   11 underside of semi-trailer floor-   12 a, b limit stop-   13 a, b outer end of partial spring-   14 upper partial spring-   15 lower partial spring-   16 mounting bushing-   17 stop point-   18 inner tube-   19 axial direction of guide tube-   20 a, b, c different positions-   21 elastic sleeve-   22 belt drive-   24 air chamber sleeve-   24 a air chamber without torsional load-   24 b air chamber with torsional load-   25 drive belt-   26 driving wheel-   27 driven wheel-   28 tension roller-   29 hand crank-   30 landing gear gearbox-   31 landing gear mounting plate-   32 bolting plate-   33 screwed connection to bolting plate-   34 connecting bolts-   35 adjusting bolts-   36 bore

1. An apparatus, comprising: arrangement of a motor on twin landinggears, particularly on a semi-trailer of a tractor-trailer, wherein thelanding gears are interconnected via a connecting shaft and can betelescoped by starting up the motor, wherein a driveshaft of the motorengages with the connecting shaft and the motor is supported on acomponent that is fixed relative to the motor, wherein the fixedcomponent is an underside of a semi-trailer floor itself, and wherein aspiral spring or a shock absorber is arranged between the motor and theunderside of the semi-trailer floor.
 2. The apparatus as claimed inclaim 1, wherein the spiral spring comprises an upper and a lowerpartial spring disposed on a guide tube, and the outer ends of saidpartial springs can each be mounted via a limit stop, wherein a mountingbushing is disposed on the guide tube between the upper and the lowerpartial spring.
 3. The apparatus as claimed in claim 2, wherein themounting bushing or the gas shock absorber is connected with the motorat a stop point.
 4. The apparatus as claimed in claim 2, wherein theguide tube is placed onto an inner tube with which it can be connectedin various positions in an axial direction.
 5. An apparatus, comprising:arrangement of a motor on twin landing gears on a semi-trailer of atractor-trailer, wherein the landing gears are interconnected via aconnecting shaft and can be telescoped by starting up the motor, whereina driveshaft of the motor engages with the connecting shaft and themotor is supported on a component that is fixed relative to the motor,wherein a spring element is arranged between the driveshaft and theconnecting shaft.
 6. The apparatus as claimed in claim 5, wherein thespring element is an elastic sleeve, a belt drive or a slip coupling. 7.The apparatus as claimed in claim 6, wherein the elastic sleeve isconfigured as an air chamber sleeve.
 8. The apparatus as claimed inclaim 5, wherein the fixed component is at least one of the landinggears, a semi-trailer floor or a vehicle support member, wherein thefixed component is rigidly connected with the motor.
 9. The apparatus asclaimed in claim 6, wherein the elastic sleeve is non-rotatably mountedon the connecting shaft and the driveshaft.
 10. The apparatus as claimedin claim 6, wherein the belt drive comprises a drive belt, which loopsaround a driving wheel non-rotatably mounted on the driveshaft and adriven wheel non-rotatably mounted on the connecting shaft.
 11. Theapparatus as claimed in claim 10, wherein the drive belt is made of anelastic material.
 12. The apparatus as claimed in claim 10, wherein afixed, elastically supported tension roller engages with the drive belt.13. The apparatus as claimed in claim 6, wherein the slip coupling has adriving gear wheel with internal teeth which is mounted on thedriveshaft and engages with a complementary driven gear wheel withexternal teeth which is mounted on the connecting shaft, wherein thedriving gear wheel and/or the driven gear wheel is mounted on thedriveshaft or the driven shaft in a non-positive fit with a predefinablefriction coefficient.
 14. The apparatus as claimed in claim 5, whereinthe driveshaft is configured as a hollow shaft.
 15. The apparatus asclaimed in claim 14, wherein the hollow shaft has a circular crosssection.
 16. The apparatus as claimed in claim 5, wherein (a) the motoris not self-locking, (b) the motor comprises an electric motor, or (c)the motor is designed for a torque of 5 to 15 Nm, or combinationsthereof.
 17. An apparatus, comprising: arrangement of a motor on twinlanding gears, particularly on a semi-trailer of a tractor-trailer,wherein the landing gears are interconnected via a connecting shaft andcan be telescoped by starting up the motor, wherein a driveshaft of themotor engages with the connecting shaft and the motor is supported on acomponent that is fixed relative to the motor, wherein the fixedcomponent is an underside of a semi-trailer floor, wherein a spiralspring or a shock absorber is arranged between the motor and theunderside of the semi-trailer floor, wherein the spiral spring comprisesan upper and a lower partial spring disposed on a guide tube, and theouter ends of said partial springs can each be mounted via a limit stop,and wherein a mounting bushing is disposed on the guide tube between theupper and the lower partial spring.
 18. The apparatus as claimed inclaim 17, wherein the mounting bushing or the gas shock absorber isconnected with the motor at a stop point.
 19. The apparatus as claimedin claim 18, wherein the guide tube is placed onto an inner tube withwhich it can be connected in various positions in an axial direction.